1. Field of the Invention
The present invention relates in general to exterior brakes for tires and more particularly to exterior brakes for tandem tires or tires which are radially closely spaced to each other on a vehicle.
2. Description of the Prior Art
Recreational vehicles, trailers and larger vehicles often have tandem axles and tires wherein tires on each side of the vehicle are closely radially spaced from each other. Usually these tires are from two to twelve inches apart at the closest portion of the treads of each. It is often desired to park such a vehicle having tandem tires for an extended period of time. During this parking it is desirable to brake or block the tires against movement, not only for safety against the vehicle rolling, but also for the purpose of securing the vehicle against theft.
There are a wide variety of blocking devices which can be placed in between the ground and tires to prevent rolling of the tires. Some of these devices can be locked to the wheel. Generally, however, a disadvantage of these devices is that they are difficult to use on muddy ground and they only can be used on one tire at a time.
Another type of device is a tandem wheel lock shown in U.S. Pat. No. 3,548,975. This device uses opposing wedges which extend between the upper and lower spaces between the tandem tires. A pair of lever links join the lower side of the upper wedge to the upper side of the lower wedge to draw the two wedges together as the leveraged linkage is moved to a locked position. A significant disadvantage of this device is that the leveraged linkage is difficult to adjust to provide a proper amount of tension so as to securely lock the wheels. The lever arm extends horizontally out from the wheels when the lever is open and such extension is not possible on vehicles with skirts over the tops of the wheels. Further, the linkage in the lever tends to pivot the wedges as the lever arms are moved to a locked position and this makes fastening the device to the tandem tires difficult. Still further, because these linkage arms pull the wedges together, the linkage which fits between the tires is necessarily large and may not fit between closely spaced tires. Finally, the wedges are not fixed to the tires so that if a sufficient force were applied they could be axially removed even when the lever arm is locked.
It is accordingly an object of the present invention to provide an improved exterior brake device for tandem wheels which is more secure and more easily fixed to the tandem wheels.
It is also an object of the present invention to provide an improved external brake for tandem tires which has a simpler construction and is more versatile than previous brakes.